From d2af9b566554e01f9ad67b330ce569dbc130e5d3 Mon Sep 17 00:00:00 2001
From: Franky Lin <franky.lin@broadcom.com>
Date: Wed, 16 May 2018 14:12:01 +0200
Subject: [PATCH] brcmfmac: validate user provided data for memdump before
 copying

In patch "brcmfmac: add support for sysfs initiated coredump", a new
scenario of brcmf_debug_create_memdump was added in which the user of
the function might not necessarily provide prefix data. Hence the
function should not assume the data is always valid and should perform a
check before copying.

Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/debug.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/debug.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/debug.c
@@ -40,7 +40,8 @@ int brcmf_debug_create_memdump(struct br
 	if (!dump)
 		return -ENOMEM;
 
-	memcpy(dump, data, len);
+	if (data && len > 0)
+		memcpy(dump, data, len);
 	err = brcmf_bus_get_memdump(bus, dump + len, ramsize);
 	if (err) {
 		vfree(dump);
